Brake



' J. SNEED Feb. 4, I930;

' BRAKE Filed June 13. 1927 2 Sheets-Sheet 1 Fuanl "Patented at. 4, 13a

JOHN snnnn, or DETROIT, MICHIGAN,

' COMPANY, or CLEVELAND,

BRAKE Application filed June 13,

This invention relates to brakes, more particularly to a multiple shoe brake having a unique flexible connection between the shoes. In the embodiment of my invention shown herewith, I use three braking shoes in an arrangement similar to; that of a well known type of automobile brake, It has been common practice in making this type of brake to form some of the shoes with arms or extensions, all of which reach across the space between shoes and join to the adjacent shoe at a point remote from the end. This form of constructionpermits a relative movement between the ends of adjacent shoes, which gives a more uniform engagement of all the shoes with the brake drum. This construction has certain mechanical. limitations-which may result in an uneven pressure on certaln shoes or portions of the shoes.

' It is among the objects of my invention to connect the shoes together with means that will transmit circumferential force from one shoe to theother, but will permit relative ra dial displacement between shoes.

-Another object is to construct the shoes so that they may be economically built and assembled. Another object is to provide a neoting the shoes together, and eliminating joints which are subject to wean.

A further object of my invention is to construct a brake which shall have self-energizing characteristics, but in which those characteristics may be so tempered and modified that danger of grabbing or freezing is eliminated. i v

Further objects willappear from the following description of the apparatus, a preferred form of which is shown :herewith. The'essentlal characteristics are summarized a 1n the claims.

In the drawings, Fig. 1 an elevation of the brake assembly; Fig. Q'is a, plan of the at tachment of theIshoe connecting means; Fig. an elevation of the shoe connecting means;

F 4 a. section of the body of the shoe; Fig. is a detail of the expanding mechanism. Referring particularly to Fig.- 1, I show the usual brake drum 1.) and the three shoes A, B and C, the shoes each having suitable lin- 1927. Serial No. 198,622,

ing as shown at L. The several shoes may be preferably formed of channel sections, see Fig. 4, although any section adapted to the principles of my invention will suflic'e.

"Referring to Figs. 1 and 5, I show an exemplary shoe expanding device which comprises a toggle linkage having certain modifications and improvements over the toggle linkage shown in my copending application Serial N 0. 48,470, filed August 6th, 1925. For the present purpose I prefer to use an expanding device which will deliver equal pressures to the ends of the shoes A and (Land which device is capable of circumferential displacement without change in force delivered.

Referring particularly to Fig. 5, the cable 10 is pulled by suitable connection with the brake pedal or other operating means, not shown. The cable is joined to the mid-point of the'toggle through the pin 11. The toggle arms 12 and 13 are also pivoted on the pin 11. Each toggle arm has a double bifurcated end by which it engages the pins 14 and 15 and 14 and 15, respectively. The pins 14 and 14 are pivotally mounted in the flange of the shoe as. at 16 and 16, and are secured against lateral displacement by suitable cotter pin as shown. The pins 14 and 14 are flattened along what appears to be the upper and lower surfaces in this disclosure to receive the major b'ifurcationsof eachof the toggle arms. The pins 15 and 15' are secured and pass through the centers of the pins 14 and 14, passing at right angles to the flattened surfaces. The pins 15 and 15' are engaged by the minor bifurcation of the toggle arms substantially as shown. It will be seen that a universal connection is provided between each toggle arm and the ends of the shoes A and C respectively.

In the disclosure of my invention shown herewith, a suitable anchorage for the friction device is provided by means of the anchor pin 20 located near the adjacent ends of the shoesB and C. A stop member 21 is provided between the adjacent ends of the shoes A and C. The stop member 21-does not serve as an anchorage when the anchor 20 is provided, but serves to center and limit the withdrawal or contraction of the shoes when ,the brake is released. A suitable retraction spring 22 is provided to withdraw the shoes from the drumonto the stop 21.

Referring particularly to Figs. 1, 2 and 3, I show the shoe connecting member 30 which in the preferred form of my invention is a leaf spring connected to the shoes A and B at points remote from their adjacent ends, as at 31 and 32. As will appear I found it advantageous to secure the member 30 over a limited zone of contact with the shoe, between points in Figs. 2 and 3. The specific connection of the member 30 to the shoe A or B, which I have found most desirable involves a mere cutting away of the side flanges of the shoe .between the points 33 and 34, and a mortising of the member 30 with extensions 35 into the cut away portions of the side flanges. A suitable bolt or rivet 36 draws the member 30 into engagement with the side flanges. The member 30 may closely fit with the inner sides of theflanges as at 37, to prevent lateral displacement.

The outstanding characteristic of this connection is that the leaf spring is joined to the shoe at a point both remote from the end of the shoe and from the lining supporting portion of the shoe, that is, the member 30,1ies a substantial radial distance inward with the brake drum.

The connection between the shoes B and C may include a member 40 similar to the member 30 and may include a second member 41, which is looped to engage the anchor pin 20. The member 40 may be an exact replica of the member 30 and may be interchangeable there-. The member 41 may be of similar mawith. terial. and along with its function of engaging the anchor pin, it also serves to brace and support the member 40. Whether the shoes are anchored at 20 or 21, I have found it desirable to use a connection of greater resiliency between the shoes B and C than between theshoes A and B, considering that the usual drum rotation is counterclockwise.

After brake shoes are forced into engagement with the drum, then immediately upon their release the resilient inner-connectlons 30 and 40 exert a radially inward force to return or release all the shoes from engagement.

. In operation the expansion means forces both the shoes A and C outwardly into con tact with the drum. Considering that the drum revolves counterclockwise, will act as a servo shoe for the shoe B, to exert a circumferential force which will be transmitted through the member 30. The member 30 being resilient will permit the whole of the shoe A to come into contact with the drum, so that it may be fully effective to serve the shoe B. In this phase of the o eration the shoe A may be momentarily ra ially displaced a greater amount than the shoe B.

33 and 34, shown particularly the shoe A The force delivered to the shoe B has two components, first, the circumferential component which is made up of the primary force delivered by the expansion device, and the secondary force caused by the frictional engagement of the shoe with the drum, and second, the radial component resulting from the bodily displacement of the shoe. The radial force exerted on,the shoe B is a result of the moment of the circumferentialforce delivered from the shoe A about the anchor 20, and the purely radial force delivered from the shoe A to the shoe B. The shoe 'B is therefore forced outwar-dl and'into engagement with the drum by the servo-action of the shoe A.

The other end of the shoe B adjacent the anchor, by reason of its resilient connection with the anchor and-by reason of the circumferential and radial distance between the point 32 and the drum and anchor, may come into full enga ement with the drum. The members 40 and 41 will flex about the anchor in response to the radial component of the total force delivered to the shoe B.

The shoe C has exerted upon it the full force of the expansion device, and may fully engage the drum from one end of the shoe to the other by reason of its resilient connec: tion to the anchor by the members 40 and 41. lVhen the drum is revolving in the reverse direction, the shoe C is fully efl'ective by virtue of its wrapping action through its resilient connection with the anchor. The resilient connection between the shoe C and the anchor pin 20 allows the full surface of the shoe 0 to actively engage the drum. The shoes A and B are urged into engagement with the full force of the expansion device.

It will be seen from the foregoing that a plural shoe brake constructed according to my invention and having such a resilient connection between shoes, permits a fuller and I more useful engagement between all of the surface of each of the shoes than could be obtained, were the shoes pivotally connected.

The device shown is rugged and is conducive to ready assembly and to ease of manufacture. It will be seen that any one of the parts so assembled may be quickly replaced, in the event of failure or wear; that each of the few parts require no detailed fitting or machining operations; and that a'very satis factory brake can be economically produced.

Iclaim:

1. A brake shoe having a circumferential lining supporting part and an inwardly extending radial reinforcing part, the inner edge of the radial part having a seat portion to receive a separate shoe connecting member.

2. A pressed metal brake shoe having a circumferential lining supporting part and M dial reinforcing flanges, the inner edges of the flanges being notched to receive a separate shoe connecting member.

3. A pressed metal brake shoe having a cir-. cumferential lining supporting part and in- 1 flanges, and an inter-connecting member, said flanges of the shoe being notched to receive the said inter-connecting member.

5. The combination of a brake shoe formedin channel cross section and having inwardly extending radial flanges, and an inter-connecting member formed as a flat piece and secured to said flanges, said flanges-of the shoe being notched along the inner edge to receive the said inter-connecting member.

6. A channel shaped brake shoe having inwardly extending radial flanges, the inner edges of the flanges being notched, an extension. member positioned in the notched portions of the flanges and means for securing the extension member to the shoe.

7. A channel shaped brake shoe havinginwardly extending radial flanges, the inner edges of the flanges being notched, anda resilient extensionmember positioned in the notched portions of the flanges and means for securing the extension member to the shoe.

8. A channel shaped brake shoe having inwardly extending radial flanges, an extension member secured on the inner edges of the flanges and extending beyond the end of the shoe, andmeans for securing the extension member to the shoe.

9. A brake shoe having inwardly extending radial flanges, said flanges being notched between the mid portion of. the shoe and one end thereof, and a member secured in the said notched portions of the flanges and extending beyond the end of the shoe.

10. A brake shoe having inwardly extending radial flanges, said flanges being notched between the mid portion of the shoe and one end thereof, and a 'leafspring member secured in the said notched portions of theflanges and extending beyond the end of the shoe.

' 11. A brake shoe having a cylindrical lining supporting portion and inwardly extending radial flanges, an extension piece adapted to engage the edges of said flanges at a point between the middle and the end shoe, and means engaging the lining supporting portion and the said extension piece and adapted to hold the extension piece in fixed relation to the shoe;

12. A brake shoe having a cylindrical lining supporting portion and inwardly extending radial flanges, a leaf spring memberadapted to extend beyond theend of the shoe and engaging the edges of said flanges at a point between the middle and the end of the shoe, and means engaging the lining supporting portion and the said member for holding the member in fixed relation to the shoe.

ing part and distant from the end of the shoe.

14. A brake shoe having inwardly extend-- ing radial flanges and a leaf spring member extending beyond the end of the shoe and se-v cured between the inwardly extending flanges of the shoe at a pointspaced inwardly from the working face of the shoe and spaced away from the end of the shoe.

15. The combination of a channel shaped brake shoe having inwardly extending radial flanges, a resilient member secured between the flanges of the shoe at a' point spaced radially inward from the working face of the shoe and spaced away from the end of the shoe and out of contact therewith whereby the resilient member is held against lateral movement relative to the shoe and the shoe may move radially with regard to a remote portion of the said resilient extension.

16. A brake shoe having a resilient extension piece secured to it at a point spaced radially inward from the working face of the shoe and spaced away from the end of the shoe and out of radial contact with the portion of the shoe between the end of the shoe and the point of attachment thereto, whereby the shoe may move radially with regard to a remote portion of the said resilient exten- SlOIl. I

17 The, combination of a brake drum, a plurality of shoes having lining supporting parts and being disposed within the drum, leaf spring members adapted 'to inter-connect the shoes and bridging the ends of the shoes, said members being secured to the shoes at points remote from the adjacent ends therepoints spaced from the lining supporting po'rtions and from the adjacent ends of the shoes and bridging the ends of the shoes at a distance spaced inwardly from the drum.

-19. The combination of a brake drum, a' plurality of brake shoes disposed within the drum, resil nt means for connecting the mg means associated with one of the resilient inter-connecting members near the ends of the two adjacent shoes, and a retraction .stop member disposed between the ends of the shoes associated With the expansion means.

20. A plural shoe brake comprising three shoes, an expansion device disposed between the ends of two of the shoes, a leaf s ring member bridging the ends of two 0 the shoes and secured to each of the shoes at points spaced radially inwardly from the working faces of the shoes and spaced away from' theends of the shoes, a second leaf spring member of less flexibility than the first leaf spring member and: connecting across the remaining shoe ends and connected to the shoes in a manner similar to the connection of the first spring member to the shoes, anchoring means associated with the last named leaf spring member in pivotal relation therewith, whereby the full working length ofea'ch ofthe shoes is forced into contactwith the drum when the expanding device 'isactuated. 4 21. A plui al-shoe brake having an expansion device'afid an anchor pin, a shoe disposed between theezjipansion device and the anchor pin, a leaf fspring extension member connected to the anchor pin and secured to the shoe at 'a pointspaced inwardly from the working face thereof and spaced away from the end of the shoewhereby the shoe may be forced intol'ngagement for its-full length.

a pair of brake shoes, means carried by adja cent ends of the shoes comprising'universal connections with the toggle and flexible interconnecting means carried by the other ends of the shoes.

29. In a brake the combination of a pair of channel shaped shoes, an expansion device disposed between adjacent ends of the shoes,

In testimony 'wher'eof, Ihereunto aflix my signature.

' JOHN SNEED.

22. The combination of a brake shoe and a'scparate' resilient piece secured thereto, said piece extending beyond the end of the shoe and spaced radially away from the end of the shoe. 1

'23. The combination of a relatively rigid brake shoe having a flat curved lining supporting part and afleaf spring member se-' cured to the shoe and extending beyond the end of the shoe and being spaced away from the lining supporting part at the end of the shoe.

24;. A channel shaped .bralie shoe having a leaf spring member secured to its flanges at one end and having a roller or' pin journalled in its flanges at the other end.

25. A brake shoe having a resilient extension at one end for engaging a part of the brake and having a rotatable pin at its other 4 end for engaging another part ofthe brake.

26. In a brake the combination of a toggle, a shoe, means associated with oneend of the shoe comprising a universal connection with the toggle and means associated with the other end of the shoe comprising a flexible piece adapted to engage an adjacent part of the brake.

27. A channel shaped brake shoe having inwardly extending side flanges and leaf 

